Oil pump for vehicle

ABSTRACT

An oil pump for the vehicle includes: a first oil pump configured to pressurize oil and discharge the pressurized oil; a second oil pump connected with the first oil pump so as to be operated by receiving power from the first oil pump, and configured to pressurize oil and discharge the pressurized oil; and a connection path configured to connect the second oil pump to the first oil pump in order to supply the oil discharged from the second oil pump to the first oil pump, to decrease power loss and be formed to be compact.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority of Korean Patent ApplicationNumber 10-2013-0112835 filed Sep. 23, 2013, the entire contents of whichapplication is incorporated herein for all purposes by this reference.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to an oil pump for a vehicle, and moreparticularly, to an oil pump for a vehicle, in which a low pressuredischarge oil pump and a high pressure discharge oil pump are seriallyconnected, and which includes one oil inlet, and one low pressure outletand one high pressure outlet.

2. Description of Related Art

An oil pump is used for lubricating a transmission or supplying workingoil of a transmission of a vehicle in the related art.

Oil with low pressure in a level of 2 to 4 bars is sufficient tolubricate or cool internal operational components of a transmission of avehicle, for example, an automatic transmission, but in order to operatean operational component, for example, a clutch, of the automatictransmission, oil with high pressure in a level of 15 to 20 bars isrequired.

Accordingly, as illustrated in FIG. 1, in order to supply necessary oilto an automatic transmission 10, each of a first oil pump 20 for lowpressure discharge and a second oil pump 30 for high pressure dischargeare mounted in the automatic transmission 10 in the related art.

The first oil pump 20 for low pressure discharge is formed of, forexample, a mechanical oil pump, and the second oil pump 30 for highpressure discharge is formed of an electric oil pump.

The first oil pump 20 for low pressure discharge and the second oil pump30 for high pressure discharge are connected with an oil storage 40 asillustrated in FIG. 2, so that the first oil pump 20 for low pressuredischarge and the second oil pump 30 for high pressure discharge formnecessary oil pressure by taking in the oil stored in the oil storage 40through the respective inlets, and supplying the oil into the automatictransmission 10 through the respective outlets.

That is, the oil pump for the automatic transmission according to therelated art has a dual structure of the low pressure discharge pump andthe high pressure discharge pump.

However, the aforementioned structure of the oil pump for the automatictransmission for the vehicle in the related art has a drawback in anaspect of a layout because each of the low pressure discharge pump 20and the high pressure discharge pump 30 need to be mounted in theautomatic transmission 10.

Further, two additional oil intake lines, which are separated from eachother, are required in order for the low pressure discharge pump 20 andthe high pressure discharge pump 300 to take in oil from the oil storage40, so that it is difficult to secure a layout, and each of the lowpressure discharge pump 20 and the high pressure discharge pump 300forms necessary pressure to discharge oil, so that in a case where highpressure is required, a load applied to the oil pump is increased,thereby increasing power loss.

The information disclosed in this Background section is only forenhancement of understanding of the general background of the inventionand should not be taken as an acknowledgement or any form of suggestionthat this information forms the prior art already known to a personskilled in the art.

BRIEF SUMMARY

Various aspects of the present invention provide for an oil pump for avehicle, which is capable of decreasing power loss of the oil pump, hasimproved high pressure response, is compact and is decreased in a sizeto have an advantageous layout.

Various aspects of the present invention provide for an oil pump for avehicle, including: a first oil pump configured to pressurize oil anddischarge the pressurized oil; a second oil pump connected with thefirst oil pump so as to be operated by receiving power from the firstoil pump, and configured to pressurize oil and discharge the pressurizedoil; and a connection path configured to connect the second oil pump tothe first oil pump in order to supply the oil discharged from the secondoil pump to the first oil pump.

The first oil pump may be an oil pump for high pressure discharge fordischarging relatively higher pressure oil than that of the second oilpump, and the second oil pump may be an oil pump for low pressuredischarge for discharging relatively lower pressure oil than that of thefirst oil pump.

The second oil pump may be communicatively connected with an oil storagefor taking in oil.

The oil pump for lower pressure discharge may include a low pressure oildischarge path for supplying the pressurized oil to the outside, and theconnection path may be branched from the low pressure oil discharge pathto be connected with the oil pump for high pressure discharge.

Each of the first oil pump and the second oil pump may be connected tothe automatic transmission so as to supply the oil to the automatictransmission.

The first oil pump may include a driving shaft rotating by receivingpower from the outside.

The second oil pump may include a driven shaft integrally and rotatablyconnected with the driving shaft in series.

Various aspects of the present invention provide for an oil pump for thevehicle including the oil pump for lower pressure discharge and the oilpump for high pressure discharge inside one oil pump housing to beconfigured to be compact, so that it is possible to decrease a size ofthe oil pump to achieve an advantageous layout.

The necessary quantity of oil in a low pressure side may be dischargedby using the quantity of oil taken in by the oil pump for lower pressuredischarge, and some of the oil boosted with the low pressure may besupplied to the oil pump for high pressure discharge through theconnection path and may be boosted to high pressure to be discharged, sothat it is possible to decrease a driving loss of the oil pump forboosting the pressure of the oil.

The oil pump for low pressure discharge and the oil pump for highpressure discharge may be serially connected with each other to bedriven with the same number of times of rotation, so that it is possibleto continuously and stably generate the quantity of discharged oil ofeach oil pump, and the quantity of oil supplied to the oil pump for highpressure discharge through a connection path from the oil pump for lowerpressure discharge is stably maintained, thereby improving high pressureresponse.

The methods and apparatuses of the present invention have other featuresand advantages which will be apparent from or are set forth in moredetail in the accompanying drawings, which are incorporated herein, andthe following Detailed Description, which together serve to explaincertain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of an oil pump for low pressuredischarge and an oil pump for high pressure discharge mounted in anautomatic transmission for a vehicle according to the related art.

FIG. 2 is a schematic diagram describing an operation of the oil pumpfor low pressure discharge and the oil pump for high pressure dischargeaccording to the related art

FIG. 3 is a cross-sectional view of an exemplary oil pump for a vehicleaccording to the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of thepresent invention(s), examples of which are illustrated in theaccompanying drawings and described below. While the invention(s) willbe described in conjunction with exemplary embodiments, it will beunderstood that present description is not intended to limit theinvention(s) to those exemplary embodiments. On the contrary, theinvention(s) is/are intended to cover not only the exemplaryembodiments, but also various alternatives, modifications, equivalentsand other embodiments, which may be included within the spirit and scopeof the invention as defined by the appended claims.

An oil pump for a vehicle according to various embodiments of thepresent invention may be used for supplying low pressure oil forlubricating or cooling an inside of an automatic transmission mounted ina vehicle, or supplying high pressure oil serving as working oilpressure of an operational component, such as a clutch or a brake of theautomatic transmission.

Referring to FIG. 3, the oil pump for the vehicle according to variousembodiments of the present invention may include a housing 100 having avolume with a predetermined size therein.

A driving shaft 110 capable of rotating by receiving power through apower source, such as an engine or a motor, may be mounted at one sideof the housing 100 to be ratably supported, and may be mounted to passthrough the one side to protrude toward an inside of the housing 100.

An oil pump 120 for high pressure discharge may be integrally androtatably mounted to the driving shaft 110.

The oil pump for high pressure discharge may be integrally and rotatablymounted to the driving shaft 110 to include an oil carrying member 122,such as a rotor or a gear, pressurizing and discharging oil whilerotating according to the rotation of the driving shaft 110.

A driven shaft 130 may be integrally and rotatably connected to thedriving shaft 110 in series. One will appreciate that such integralcomponents may be monolithically formed.

The driven shaft 130 may be rotatably supported inside the housing 100.

An oil pump 140 for low pressure discharge may be integrally androtatably mounted on the driven shaft 130.

The oil pump 140 for low pressure discharge may be integrally androtatably mounted on the driven shaft 130 to include an oil carryingmember 142, such as a rotor or a gear, pressurizing and discharging oilwhile rotating according to the rotation of the driven shaft 130.

An oil intake path 102 communicating with the oil pump 140 for lowpressure discharge may be provided at the housing 100.

The oil intake path 102 may be elongated from one external surface ofthe housing 100 to the oil pump 140 of the low pressure discharge.

An entrance of the oil intake path 102 may be connected with an oilstorage 150 capable of storing the predetermined volume of oil.

Accordingly, when the oil pump 140 for the low pressure discharge isoperated, the oil stored in the oil storage 150 is taken in up to theoil pump 140 for low pressure discharge through the oil intake path 102.

A low pressure oil discharge path 104 for supplying the oil dischargedfrom the oil pump 140 for low pressure discharge to the outside may beprovided at the housing 100.

The low pressure oil discharge path 104 may be formed of an additionalline separated from the oil intake path 102 in the housing 100.

The low pressure oil discharge path 104 may be elongated from the oilpump 140 for low pressure discharge to one external surface of thehousing 100.

An outlet of the low pressure oil discharge path 104 is communicativelyconnected with, for example, the inside of the automatic transmission,so that the low pressure oil discharged through the low pressure oildischarge path 104 is supplied to the inside of the automatictransmission to be usable for lubricating or cooling the operationalcomponents of the automatic transmission.

A connection path 106 communicating with the low pressure oil dischargepath 104 may be formed at a partial section of the low pressure oildischarge path 104.

One end of the connection path 106 may be formed to communicate with thelow pressure oil discharge path 104, but the other end of the connectionpath 106 may be elongated to communicate with the oil pump 120 for highpressure discharge.

Accordingly, the low pressure oil discharged from the oil pump 140 forlow pressure discharge is supplied to the automatic transmission throughthe low pressure oil discharge path 104, and some of the low pressureoil discharged from the oil pump 140 for low pressure discharge issupplied to the oil pump 120 for high pressure discharge through theconnection path 106 to be boosted in the oil pump 120 for high pressuredischarge again.

In order to supply the high pressure oil discharged from the oil pump120 for high pressure discharge may be elongated from the oil pump 120for high pressure discharge to one external surface of the housing 100.

An outlet of the high pressure oil discharge path 108 is communicativelyconnected with, for example, the inside of the automatic transmission,so that the high pressure oil discharged through the high pressure oildischarge path 108 is supplied to the inside of the automatictransmission to be usable for operating the operational components ofthe automatic transmission, for example, a clutch or a brake.

The foregoing descriptions of specific exemplary embodiments of thepresent invention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteachings. The exemplary embodiments were chosen and described in orderto explain certain principles of the invention and their practicalapplication, to thereby enable others skilled in the art to make andutilize various exemplary embodiments of the present invention, as wellas various alternatives and modifications thereof. It is intended thatthe scope of the invention be defined by the Claims appended hereto andtheir equivalents.

What is claimed is:
 1. An oil pump for a vehicle, comprising: a firstoil pump configured to pressurize oil and discharge the pressurized oil;a second oil pump operably connected with the first oil pump so as to beoperated by receiving power from the first oil pump, and configured topressurize oil and discharge the pressurized oil; and a connection pathconfigured to fluidly connect the second oil pump to the first oil pumpin order to supply the oil discharged from the second oil pump to thefirst oil pump.
 2. The oil pump of claim 1, wherein: the first oil pumpis an oil pump for high pressure discharge for discharging relativelyhigher pressure oil than that of the second oil pump; and the second oilpump is an oil pump for low pressure discharge for dischargingrelatively lower pressure oil than that of the first oil pump.
 3. Theoil pump of claim 1, wherein the second oil pump is in fluidcommunication with an oil storage for taking in oil.
 4. The oil pump ofclaim 2, wherein: the oil pump for lower pressure discharge includes alow pressure oil discharge path for supplying the pressurized oil to theoutside; and the connection path is branched from the low pressure oildischarge path to be connected with the oil pump for high pressuredischarge.
 5. The oil pump of claim 1, wherein each of the first oilpump and the second oil pump is connected to the automatic transmissionso as to supply the oil to the automatic transmission.
 6. The oil pumpof claim 1, wherein the first oil pump includes a driving shaft rotatingby receiving power from the outside.
 7. The oil pump of claim 6, whereinthe second oil pump includes a driven shaft integrally and rotatablyconnected with the driving shaft in series.